Hot melt adhesives are adhesives that are able to adhere to various products efficiently since they solidify in a short time, and are highly safe to human body since the adhesives do not require solvents. Therefore, hot melt adhesives are used in a variety of fields. For example, hot melt adhesives are commercially used as adhesives for sealing wrapping papers, packaging cardboard, and packaging films for food, clothes, electronic devices, and cosmetics; when sanitary products such as diaper and sanitary goods are produced, as an adhesive to adhere members configured therein; and as an adhesive configured in an adhesive layer of an adhesive tape and label.
Hot melt adhesives are usually produced by blending a substance such as a tackifying resin in a base polymer. In recent years, as the tackifying resin, hydrogenation of a hydrocarbon resin has been attempted from the viewpoint of improving color and odor of hot melt adhesives.
For example, it is described in Patent Literatures 1 to 2 that the color is improved by hydrogenating a hydrocarbon resin.
Also, in such a hydrocarbon resin hydride, changes in color due to factors such as deterioration by heat is less, and the odor is improved since an unsaturated bond originally included in the hydrocarbon resin is saturated by a hydrogenation reaction (hydrogenating).